microdon2

My Feedback: (47)

Good feedback - makes sense. I'll try opening the needles. Thanks.

Ernie Misner

Any air bubbles coming through the line before it quits? Hopefully richening it up will solve the problem. If not, could be a bad carb or diaphram, or even burrs on the plastic reed valve block causing the reeds to not be seating properly. No need for the tank to be placed in line with the carb like nitro engines.

Lifer

My Feedback: (1)

If you are adventurous, you can lap the reed valve cages to get a better seal. This will improve the fuel draw. Also, I agree with your settings being a little too lean.

microdon2

My Feedback: (47)

Gents - had a bad crash a month ago (lost an aileron servo) and have rebuilt the engine (new crank shaft and crank case, bearings, carb, EI from another engine).

Just put the new carb on tonight. Had trouble starting - it fired, but then died. Plug was wet - figured I flooded it - let it air out. Noticed that the LS came set at 1.5, but the manual says 1.1, so I closed it to 1.1. (HS at 1.5) Engine now starts up and transitions nicely to WOT, but keeps dying on idle. It slowly dies, like it's too rich. I keep closing the LS, which seems to help, but then it slows and dies again. I've now got the LS down to 3/4 - should I keep going? Someone once told me his DLE 20 LS was at 5/8. My old carb LS - I thought - was at around 1. Could it be that I'm using an EI from another engine? (I would not think that would affect the idle, but...)

Thanks.

clive45

I believe that the DLE 20 has a special ignition to give good idle so ignition from another motor may be causing the problem if it was not a DLE20

flyin two low

My Feedback: (44)

I bought a dle 20 without ignition, since i had an aftermarket ignition i saved a little money i thought. I had idling problem and after lapping reed valve block with no help. i bought an ignition for dle 20 and like magic problem solved.

clive45

I would say that the ignition timing for the DLE20 has a very different timing below a certain RPM for good idle so they can use correct timing for very good power in the higher RPM's where as other motors do not.

mach2

My Feedback: (5)

I hated the timing step of the DLE 20 ignition. It took a few seconds to settle into a good idle when I would bring the throttle all the way back. It was a pain in the butt during landings. So when I wrecked it and ruined the cdi, I bought a cdi for a DLE 30. It ran better. What cdi is it exactly?

From your description I'd say it's got something to do with the carb. Where did you get the carb?

w1nd6urfa

My Feedback: (4)

Is the compression good? prop / spinner balanced?
both could affect idle and are easy to check and rule out - since you replaced crankshaft after the crash I wouldn't be surprised if the conrod/sleeve are slightly bent, wouldn't notice at wot but will roughen the idle

KEY QUESTION: when the engine stops, does it "freeze" in one spot or it bounces to compression back and forth until it settles?
If it seems to freeze then you've got bent sleeve.

A bit more far-fetched, but after ruling out any mechanical issues I would check the floater in the carb.
On a new DLE I had similar issues, opened the carb and discovered an aluminum scrape on the floater seat causing the engine to be rich regardless of needle settings

microdon2

My Feedback: (47)

It's a Pegasus CDI, seems pretty generic, and it's also the exact same brand \ model that I had in the DLE20 when it crashed, and that seemed to run fine at idle.

I just check the bent sleeve idea - just flipped the prop a few times - it does stop all of a sudden. I have another DLE20 on another plane and it bounces back and forth freely before stopping. The head on the damaged engine DID take a hit - there are broken fins on the top front edge. Does that mean the head needs to be replaced? (was trying to avoid that...)

w1nd6urfa

My Feedback: (4)

How does the compression compare between the 2 DLEs? If on the refurbished you hear a hiss and compression is not great, then new cylinder I'm afraid

ahicks

My Feedback: (2)

microdon2, you've seen the procedure for adjusting the carbs haven't you? Wide open first, then the idle? That's where I would start. See where you are at afterward.

Keep in mind no 2 carbs are alike, otherwise these settings would be standardized. Starting settings are just that, to get the engine started. Once that's done, forget those settings and use whatever it takes to get it to run right. Also, no point in spending a lot of time getting the settings perfect on the ground. You know they're going to change once airborne....

BTW, I wouldn't worry too much if this engine isn't as "free" as another. It's just been completely apart, and parts might need to be run in a little to seat properly. Last, if the bearings aren't fully seated, and the crank fully seated in the bearings (not unusual after a nose first....."incident") , the pin and rod could be dragging on the back case a little. -Al

Muttdog

Are you sure it is the right carb? is it clean? If you can run at 3/4 on the LS (or lower) and have good transition then something's wrong. Mine won't even accept throttle with anything below 1 turn and I would never dare take off at that setting or a deadstick would be imminent. I'm much closer to the 1.25 - 1.5 range on the LS (sea level high humidity) and that is the same for all 20's I've helped others with. I would start at the fuel system

microdon2

My Feedback: (47)

This is a DLE20 carb from Tower. I've had a few of these and the 3/4 LS doesn't seem right to me. I will take it apart and look at the needle float to see if it's got debris in there. Or could be a leak in my fueling system. Also might just swap heads with my other DLE20. I know at some point all this troubleshooting is overkill, but, at this point, I really want to identify the problem.

Ahicks - I hear you, that things might need to re-seat, but this engine is really not flyable, as I'd either need to leave the idle too high to land, or I'd be in danger of stalling on each idle spot (landing, hammerheads). The way this engine is acting I like the "bent cylinder" idea. Will look at this when I get home. Also will replace the boot on the EI and see if that still works. (if not, I should have just bought a new engine!)

Thanks for the help so far.

microdon2

My Feedback: (47)

Last night I swapped heads between my healthy (never crashed) and rebuilt DLE20's. The healthy engine ran fine with the damaged (broken fins, at least) head, including a steady low idle, so it seems that the piston cylander isn't bent after all (is THIS why we have so many engines??). So I've now got the undamaged head on the rebuilt engine and there is still some degree of "stopping" when I flip the prop. It's not horrible, and sometime the prop bounces back in the other direction (like the healthy 20), but it does tend to stop a bit in the middle. Just rotatiing the spinner the engine feels free, and flipping the prop feels like the same degree and points of resistance. Maybe I have the bearings in slightly askew? Or maybe the end of the crankshaft is touching the backplate.

On the upside, I dont' have to buy a new head. Also I fixed the damaged EI (put on a new plug cap), taped the box back together (the insides look fine), hooked it up and got a spark! Question, though - for the EI plug cap - does it matter which direction the resister goes in? one side has a white strip, the other brown. I think I installed it with the thicker lead (doubled over) inside the cap, and the thin (single) lead in the wire side. I'm guessing direction doesn't matter, and I DID get a spark, but would like input on that one.

Also took the carb apart - some minor debris in the screen, float valve needle and seat were clean, pump membrane looked fine.

Will test the engine tomorrow, and with this EI, the same one that was in there during the crash (which had the engine running fine, so that should eliminate the EI as the cause, as long as this patched-up EI works 100%). Also opened the LS back to 1.1 turns. If this engine STILL has problems in idle I'll then look at the backplate and the bearings.

JNorton

My Feedback: (2)

A resistor doesn't care which way it is installed.
John

microdon2

My Feedback: (47)

Got the rebuilt DLE 20 running, using the original EI (fixed from the crash). Still seems to bog down on the low end, but slowly. It's manageable. I opened the LS to 1.25 and raised the low idle throttle setting (I did try leaning the LS, but it didn't seem to help.) I'm going to run it for a while like this to see if it changes \ settles in \ breaks in. One difference I noticed between the two engines - the other DLE 20 (which now has the damaged head) - during prop rotation by hand - you feel one point of resistance. The rebuilt engine - with the newer (not many hours) head, has TWO resistance spots. I took the muffler off and you could then see that the resistance spots were exactly when the piston started going into compression, then a slackness at TDC, then more resistance coming down - which seems to me is what you would expect (so why does the other have only ONE spot? Frank Bowman ring in the rebuilt and not in the new 20, thus creating more compression \ resistance?) Maybe this new head just isn't broken in (as least, it's new for this piston). I also changed the prop from a 15x10 to a 16x8, to give it more of a "flywheel" effect, possibly keeping more momentum on low RPM's. Seems pretty good now - though not perfect. Will fly it tomorrow (in the snow) and see what happens.

microdon2

My Feedback: (47)

Took the backplate off of the rebuilt 20 and, just for ****s and giggle, banged the crankshaft forward, just in case it was back a bit and touching the backplate (though the backplate was not scratched, so..) Put the engine back together and ... now the prop seems to be moving freely. The prop bounces back and forth after flipping, like it should. Doesn't come to a sudden stop anymore. So I guess I did something right. Didn't have a chance to re-start the engine, so I may need to re-adjust the LS and throttle. Will see how it runs tomorrow morning in the snows of Long Island.

w1nd6urfa

My Feedback: (4)

That's good troubleshooting microdon2, eliminating all possible causes one at a time. You're either alright now, or very close

ahicks

My Feedback: (2)

Yup, sounds like you have the problem on the run now. Best of luck on the "remaiden" - and your weather....

or170b

My Feedback: (3)

Was wanting to get some feedback on prop selection for this engine. I have it installed on a TF 60 size mustang.

Lifer

My Feedback: (1)

16x8 is a good start. 17x6 if you want to go a little slower. I have heard some use a 15x10 but I have no experience with that choice.

mach2

My Feedback: (5)

17x6 has great pull and is still plenty fast. If you want really fast go 16x8. If you want crazy fast 15x10. Honestly I think the 17x6 is the best over all. Over the years I've seen the majority of others recommend the 17x6 too. I'd start there and then you can decide if you want more speed.

flyin two low

My Feedback: (44)

17x6 is good all around selection. especially for 3d. 16x8 if you need ground clearance.

ahicks

My Feedback: (2)

We're talking Mustang here. I doubt it will be doing much in the way of 3D? Agree on 16x8 for the first few flights and getting it dialed in. After that, or if you have experience with this kind of performance, I wouldn't be shy of the 15x10 at all.